The Transport System in Man
Aka Circulatory System/Cardiovascular System
Notes
Definition of Circulatory System
A system comprising of the heart, blood and blood vessels which efficiently transports
blood, nutrients and other essential materials to cells while removing waste substances from
the body.
3 Major Components:
1. Heart
2. Blood
3. Blood Vessels
Humans have a closed transport system. This means that blood is transported in a network of
blood vessels which separate it from the outer environment.
Importance of Circulatory System:
Humans have a LOW surface area to volume ratio.
The interior cells of humans are too far from the surface of the body surface for diffusion to
be relied on to bring oxygen and nutrients to body cells and to remove metabolic waste.
List of Substances that Need to be Transported Around the Body
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Waste materials: eg. carbon dioxide to lungs, urea to kidneys
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Hormones: Adrenaline, insulin from endocrine glands to target organs
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Antibodies
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Blood proteins
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Blood cells
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Nutrients
The Heart
-Muscle made of specialised myocardium cells designed to pump blood around the body
2 types of blood are pumped at the same time:
1. Oxygenated blood
2. Deoxygenated blood
Thus, this system is known as a Double Circulatory System.
Deoxygenated blood is transported
Comprises of 4 spaces called chambers
-Upper chambers: Atrium (pl. atria)
-Lower chambers: Ventricles
-Thick muscle in middle of heart that separates the heart in two sides: Septum
These 2 sides are known as the left side and right side of the heart. The left side pumps
oxygenated blood to the body cells while the right side pumps deoxygenated blood to the
lungs to become oxygenated and release waste substance to be breathed out.
Oxygenated Blood → Body cells
Deoxygenated Blood → Lungs
Arteries carry oxygenated blood away from heart to the body cells.
EXCEPT! Pulmonary artery: Transports deoxygenated blood from heart to lungs
Veins carry deoxygenated blood to the heart from body cells.
EXCEPT! Pulmonary vein: Transports oxygenated blood to the heart from lungs
Major Blood Vessels in Heart:
1. Vena Cava
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•
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Main vein that transports deoxygenated blood back to the heart
Comprises of Superior Vena Cava and Inferior Vena Cava
Superior (Upper) transports deoxygenated blood from head, neck, arms
and chest to the heart
Inferior (Lower) transports deoxygenated blood from lower part of
body
2. Aorta
• Transports oxygenated blood to the body cells
3. Pulmonary Artery
• Transports deoxygenated blood from heart to lungs
4. Pulmonary Veins
• Transports oxygenated blood to the heart from lungs
5. Coronary Arteries
• Heart’s own blood vessels which supply it with blood to maintain its
function
Major Arteries and Veins in Different Regions of the Body
Region of Body
Head
Arms
Lungs
Liver
Intestines
Kidneys
Legs
Main Artery
Carotid Artery
Brachial Artery
Pulmonary Artery
Main Vein
Jugular Vein
Brachiocephalic Vein
Pulmonary Vein
Hepatic Artery
Hepatic Vein
Mesenteric Artery
Hepatic Portal Vein
Renal Artery
Iliac Artery
Renal Vein
Iliac Vein